{
  "annotation_id": "d28642e8-e2c8-459a-9dce-34d8fb8e061d",
  "date_created": "2026-03-02T18:02:16.990000Z",
  "date_modified": "2026-03-02T18:02:16.990000Z",
  "file_hash": "d9c3d3b9f913c79de83e8f0fad6bddad562ab10a48b5bce61356b7620a01e7a9",
  "private": false,
  "record": {
    "abstract": "We present a method to construct entanglement measures for pure states of\nmultipartite qubit systems. The key element of our approach is an antilinear\noperator that we call {\\em comb} in reference to the {\\em hairy-ball theorem}.\nFor qubits (or spin 1/2) the combs are automatically invariant under\n$SL(2,\\CC)$. This implies that the {\\em filters} obtained from the combs are\nentanglement monotones by construction. We give alternative formulae for the\nconcurrence and the 3-tangle as expectation values of certain antilinear\noperators. As an application we discuss inequivalent types of genuine four-,\nfive- and six-qubit entanglement.",
    "arxiv_id": "quant-ph/0506073",
    "authors": [
      "Andreas Osterloh",
      "Jens Siewert"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1142/S0219749906001980",
    "journal_ref": "Int. J. Quant. Inf. 4, 531 (2006)",
    "title": "Entanglement monotones and maximally entangled states in multipartite   qubit systems",
    "url": "https://arxiv.org/abs/quant-ph/0506073"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "ad09852a-c762-4ffc-a8c7-cb220c27a7e1",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}